An air conditioning system, such as for an automotive vehicle, comprises a compressor that delivers compressed refrigerant to a condenser, wherein heat is extracted from the refrigerant. The refrigerant flows from the condenser to an evaporator that expands the refrigerant to extract heat from the ambient. The spent refrigerant is recycled from the evaporator to the compressor. The compressor typically comprises pistons that reciprocate within cylinder chambers to draw in the spent refrigerant, compress the refrigerant, and discharge the compressed refrigerant to the condenser. Within the compressor, the refrigerant travels through a head that includes a suction chamber for supplying spent refrigerant to the cylinders and a discharge chamber that receives the compressed refrigerant. Suction ports with valves regulate refrigerant flow from the suction chamber to the cylinder chambers, whereas discharge ports with valves regulate refrigerant flow from the cylinder chambers to the discharge chamber.
The refrigerant within the suction chamber exhibits a relatively low pressure within the system. During the suction stroke, the piston is withdrawn to increase the volume within the cylinder chamber, and the valve opens to admit refrigerant through the suction port. Refrigerant flow into the cylinder chamber produces a temporary drop in the pressure of suction-side refrigerant. As each piston successively cycles through the suction stroke, the result is a regular fluctuation in suction-side pressure, referred to as pressure pulsation. This pressure pulsation is noticeable not only within the suction chamber, but also through the line to the evaporator, and results in vibration and increased noise within the system. Moreover, there is a desire to reduce the number of pistons within the compressor to thereby reduce cost and weight. However, pressure pulsation becomes more noticeable as the number of pistons is reduced, thereby increasing the associated flow-induced vibration and noise problems.
Therefore, a need exists for a compressor for an automotive air conditioning system having a suction chamber that confines pressure pulsation and thereby minimizes propagation of flow-induced vibration and noise through the suction-side components.